My sister split up with her partner six months ago. It was a ugly breakup. He spent three years controlling every move she made, isolating her from us, and screaming in her face over nothing. We spent months picking up the pieces and helping her get out. Now she’s announced they are "giving things another go."
Our mum’s 60th birhday dinner is next weekend. It’s a small family gathering, ten of us at a restaurant. Yesterday my sister texted the family group chat saying he’s coming with her.
I messaged her privately and said no fucking way. I told her he isn't welcome around the family after everything he put her through, and that turning mum's celebration into a tense dinner isn't fair.
She’s now refusing to come at all and claiming I'm deliberately sabotaging her relationship and ruining mum's big day. Mum is upset and asking me to just keep the peace for one night. I refuse to sit at a dinner table and act like everything is fine with a man who's brokeen my sister down for years.
AIBU to draw the line here, or should I just shut up for mum's sake?